Sprint Nextel Corp. (S) wound up the top dud in PC World's second annual nationwide phone network speed test. The carrier finished the 2012 test in the same place that it finished in 2011 -- last. The nation's only unlimited network is also the nation's most abysmal network in terms of speed. In 3G and 4G tests across 13 cities, Sprint proved to be as much as 6 times as slow as it next nearest competitors.

In (true) 4G, though, Verizon Wireless has the nation's largest LTE network (covers ~200M+ Americans). The company narrowly beat AT&T in uplink speed average 5.86 Mbps versus AT&T's 4.91 Mbps. However, despite its strong speeds and strong performance Verizon Wireless's 4G devices are reportedly suffering from a problem of 3G fallback -- given that Verizon's 3G (CDMA) network is so much slower than its 4G network.

By contrast, AT&T won the downlink LTE test (9.12 Mbps vs. 7.35 Mbps from Verizon), and also won PC World's honors for best LTE carrier. While the testers took issue with AT&T's coverage, which is still relatively small (~70 million Americans), they praise AT&T's pairing of HSPA+ and LTE, which allows for smoother handoffs when the faster 4G signal cuts out. They suggested that videos or other streaming content may stutter on Verizon when they lose 4G, but will continue to play smoothly on AT&T.

Overall the tests indicate AT&T and T-Mobile to be the best choices from a data perspective, with Verizon getting small honors for its wide LTE coverage and fast data speeds for LTE. Sprint was the only wholesale loser -- its 3G was the slowest out there and its 4G WiMAX was slower than AT&T and T-Mobile's HSPA+ advanced 3G.

"Nowadays, security guys break the Mac every single day. Every single day, they come out with a total exploit, your machine can be taken over totally. I dare anybody to do that once a month on the Windows machine." -- Bill Gates